Display panel or portion thereof with a graphical user interface



The sole FIGURE is a front view of a display panel or portion thereofwith a graphical user interface showing our design.

The outermost broken line rectangle illustrates a display panel orportion thereof that forms no part of the claimed design. The remainingbroken lines, including all text, illustrate portions of the graphicaluser interface and mixed reality environment that form no part of theclaimed design.

CLAIM The ornamental design for a display panel or portion thereof witha graphical user interface, as shown and described.